The claimed invention relates to a balance shaft seal clamp that holds the front balance shaft seal in place on the oil pump housing of a timing belt assembly in an automobile.
Numerous types of clamps and retainers have been developed over the years for holding bearings, oil seals, and other devices in engines. Typically, one skilled in the art designs retainers and clamps to satisfy a specific objective or requirement. As a result, the clamps and retainers in the prior art consist of a variety of designs. Indeed, some known prior art includes a bearing retaining plate (U.S. Pat. No. 4,128,283), a wear sleeve oil seal (U.S. Pat. No. 4,337,954), a removable retaining plate (U.S. Pat. No. 4,768,973), a hold down bearing retainer (U.S. Pat. No. 4,905,299), a retention plate assembly for retaining a lock (U.S. Pat No. 4,930,822), and a recoil spring end retainer (U.S. Pat. No. 5,067,451).
In addition to the clamps and retainers referenced above, the prior art also discloses a balance shaft retainer (U.S. Pat. No. 5,839,406). A balance shaft seal is a planar annular seal mounted about the balance shaft of an engine. When mounted, the balance shaft seal sits in an annular indentation on the oil pump housing. The purpose of a balance shaft seal is to prevent oil from leaking out of the oil pump housing. As oil pressure pushes against the balance shaft seal, the pressure may displace the balance shaft seal from its annular seat. Consequently, oil may leak out of the engine. A balance shaft seal retainer is designed to hold the balance shaft seal in place. U.S. Pat. No. 5,839,406 discloses a generally square planar balance shaft seal retainer with a front smooth face, rear smooth face, and a square cut on the bottom edge. The seal retainer mounts on the oil pump housing via bolts and planar ring shaped spacers. As oil pressure continuously pushes against the balance shaft seal, the square cut on the bottom edge is intended to encompasses and hold the balance shaft seal in place.
While the balance shaft seal retainer in the prior art does generally prevent the front balance shaft seal from being pushed out of place, the bottom edge holding the balance shaft seal may deform over time. Oil pressure from within the oil pump housing may bend the balance shaft seal retainer, thereby pushing the balance shaft seal out of place and resulting in oil loss and engine failure. Installation of the prior art seal retainer is also difficult. A balance shaft seal retainer is mounted on the oil pump housing by threading one or more bolts through one or more apertures in the balance shaft seal retainer and into threaded bores in an oil pump housing. Since the prior art seal retainer is planar and must be mounted on a non-planar surface of the oil pump housing, spacers are required to support the prior art seal retainer from the recesses of the engine. Furthermore, the prior art model seal retainer obstructs a mechanic""s view of the upper timing mark on the oil pump housing during and after installation. Accordingly, the prior art seal retainer may impair certain types of engine repair. In these respects, the prior art balance shaft seal retainer is difficult to use and does not effectively hold the balance shaft seal in place.
In accordance with preferred embodiments of the present invention, some of the problems associated with the prior art seal retainers are overcome. The subject invention defines the details of an improved balance shaft seal clamp. One object of the invention is to provide a one piece balance shaft seal retainer for securing the front balance shaft seal in the oil pump housing such that oil pressure does not push the balance shaft seal out of place.
It is another object of the present invention to provide a one piece balance shaft seal retainer that, when installed, semi-circularly encompasses the annular balance shaft seal and does not torsionally deform over time.
It is still another object of the present invention to provide a one piece balance shaft seal retainer that can be installed without removing the timing or balance belt.
Still another object of the present invention to provide a one piece balance shaft seal retainer with a ridged profile that permits the balance shaft seal retainer to be fitted within the recess of the oil pump housing without the need for spacers.
It is still another object of the present invention to provide a one piece balance shaft seal retainer with one or more apertures to permit timing belt marks to be visible both during and after installation of the balance shaft seal retainer.
The balance shaft seal retainer described herein accomplishes these objectives with a configuration that is generally rectangular with a semi-circular bottom edge cutout. The novelty of the present invention, in part, relies on semi-circular bottom edge. The semi-circular bottom edge effectively holds the annular balance shaft seal in place. Unlike the prior art, the bottom edge is less prone to deformation and does not obstruct the view of the timing marks on the oil pump housing.
The profile of balance shaft seal retainer is also novel. The profile of the present invention is generally non-planar, comprising a ridged front face and complementary rear indented face. The profile is configured to contour around an annular indentation on the oil pump housing where the balance shaft seal sits about the balance shaft. When mounted, the retainer is flush against the oil pump housing and the semi-circular bottom edge is flush against the balance shaft seal. As such, spacers are not needed to hold the balance shaft seal in place.